Bit inversion in memory devices

ABSTRACT

Bit inversions occurring in memory systems and apparatus are provided. Data is acquired from a source destined for a target. As the data is acquired from the source, the set bits associated with data are tabulated. If the total number of set bits exceeds more than half of the total bits, then an inversion flag is set. When the data is transferred to the target, the bits are inverted during the transfer if the inversion flag is set. 
     Alternatively, an acquired data stream includes an association with an inversion bit. The inversion bit is acquired and stored separately from the data stream. As the data stream is transferred, if the inversion bit is set then the stream is inverted during the transfer of the stream to a target.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation under 37 C.F.R. 1.53(b) of U.S.application Ser. No. 09/944,993 filed Aug. 30, 2001, now U.S. Pat. No.7,549,011 which application is incorporated herein by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to data transfers in memorydevices, and in particular, the present invention relates to bitinversions on data transfers occurring between memory devices.

BACKGROUND OF THE INVENTION

In a memory device it is desirable to read and write data in the fastestmanner possible while using the least amount of current or power aspossible. As such, multiple bytes of data are often written to or readfrom one memory device to another memory device during a singleoperation. For example, during a write operation the data bits which arecharged can draw current from the memory device while the data isstored. Thus, the more bits associated with the data that are set (e.g.,charged having a value of “1”), the more power expended by the memorydevice during the write operation. However, it will be readilyappreciated by those skilled in the art that some technology, whichpermits the programming of bits which are not set, such as NAND memory,can draw current during a write operation for bits that are not set(e.g., having a value of “0”).

With the recent explosion in consumer demand for miniaturized portabledevices (e.g., digital cameras, portable audio players, personal digitalassistants, digital phones, and the like), the ability to efficientlyprogram data in these devices and to minimize the power usage associatedwith these devices are of increasing importance. This is particularlyimportant in flash memory devices, where the performance speed of theflash memory is adversely affected by the availability of an adequatepower supply during write operations. Flash memories include arrays offlash cells, or transistors, that are electrically programmed usingrelatively high drain and gate bias voltages. However, designers ofelectrical systems that incorporate flash memories prefer not to includehigh voltage supplies in the electrical systems in order to reduceelectrical system cost and power consumption. As a result, flashmemories are designed for use with low voltage supplies having voltages,for example, as low as three volts.

Flash write operations require a relatively substantial current. Forexample, it is common to use 500 microamps per memory cell during awrite operation. A two-byte write operation, therefore, requires 8milliamps of current at a six-volt power supply. This power is not amajor concern where an external Vpp supply is available. However, in lowvoltage memory devices the availability of this external supply is ofteneliminated. Thus, the flash memories are also designed to include chargepumps to create the required higher Vpp supply voltages. In addition,internal Vpp supply generators or charge pumps are limited, primarilydue to economic reasons, in the amount of current which can be providedduring write operations.

Conventional charge pumps can simultaneously program only relatively fewflash cells. The number of memory cells, therefore, written during onewrite cycle is reduced into segments. One typical 16-bit programmingoperation is performed 4 bits, rather than 16 bits, at a time. Thissegmented programming operation significantly increases the programmingtime of flash memories. For example, a flash memory which is specifiedto operate a three volt power supply may be limited to writing 4 bits ofdata at once. To write two bytes of data, four separate write operationsare required. Similarly, a flash memory which is specified to operate atsix volts may be limited to writing one byte of data at once.

To reduce the current associated with programming memory, the bitsassociated with the data may be buffered into packets and stored in avolatile memory storage within the memory device. Next, the packets inthe volatile memory are interrogated to determine the total number ofset bits within each packet. If the total set bits within a packetexceeds more than half the total bits contained within the packet, thenthe packet is inverted before it is programmed or transferred to a nonvolatile storage associated with the memory device. In this way, thecurrent draw is reduced during the write operation. However, each datapacket is passed over twice, namely with a first pass that buffers thepacket in a volatile storage and then with a second pass that evaluatesthe packet to determine whether or not an inversion on the packet needsto occur. Accordingly, the process requires excess current to performthe second pass and it further creates unnecessary latency during thedata transfer.

Alternatively, some memory devices elect not to buffer the data as it istransferred from a source to a target (e.g., non volatile storage). Thisreduces the need for a volatile storage during the data transfer, butdoes not necessarily increase the performance associated with the datatransfer since, as will be apparent to those skilled in the art, if thedata being transferred has more than half of its data bits set, then thecurrent draw will be increased to perform the storage in the nonvolatile storage. Correspondingly, memory devices which do not bufferthe data during a data transfer consume greater amounts of power.

As is readily apparent any improvements, associated with the transferspeed and the current draw occurring during a data transfer to a nonvolatile storage in a memory device, is highly desirable andsignificant. Memory devices continue to be miniaturized requiringsub-lithographic dimensions of the electro-mechanical structurescomprising the devices. At the same time, these devices are performingmore complex operations and demanding less power.

Therefore, there is a need to reduce the data transfer time occurringwithin a memory device, particularly a flash memory device. For thereasons stated above, and for other reasons stated below which willbecome apparent to those skilled in the art upon reading andunderstanding the present specification, there is a need in the art fora memory device which can operate using a low voltage supply having anincreased data transfer throughput during data transfer operations.

For the reasons stated above, and for other reasons stated below whichwill become apparent to those skilled in the art upon reading andunderstanding the present specification, there is a need in the art foralternate implementations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a memory system for transferring a data stream according tothe teachings of the present invention;

FIG. 2 is a flowchart of methods for transferring a data streamaccording to the teachings of the present invention;

FIG. 3 is a schematic diagram of functional data operable to be invertedaccording to the teachings of the present invention;

FIG. 4 is a schematic diagram of inversion data transfer systemsaccording to the teachings of the present invention;

FIG. 5 is a flowchart of a method of inverting transferred dataaccording to the teachings of the present invention;

FIG. 6 is a schematic diagram of a system for transferring a data streamaccording to the teachings of the present invention;

FIG. 7 is a schematic diagram of a memory apparatus according to theteachings of the present invention; and

FIG. 8 is a schematic diagram of a state machine according to theteachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of the invention, reference ismade to the accompanying drawings which form a part hereof, and in whichis shown, by way of illustration, specific embodiments in which theinvention can be practiced. In the drawings, like numerals describesubstantially similar components throughout the several views. Theseembodiments are described in sufficient detail to enable those skilledin the art to practice the invention. Other embodiments may be utilizedand structural, logical, and electrical changes may be made withoutdeparting from the scope of the present invention. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present invention is defined only by the appendedclaims, along with the full scope of equivalents to which such claimsare entitled.

The term “data stream” as used in this application is intended to be anydata packet whether fixed or variable. At its lowest level the dataincluded within a data stream includes a sequence of bits, with each biteither set (e.g., value of “1”) or unset (e.g., value of “0”). Howeveras will be appreciated by those skilled in the art, memory or processingdevices typically deal with data packets in byte (8 bits) chunks thatcombine to form words, the words are in lengths that are an exponentialof 2 (e.g., 2⁵ or 32, 2⁶ or 64, and the like).

With fixed length data packets, the size of the packet is constant anddoes not vary. Conversely, a variable length packet reserves bits orbytes at the start of the data packet indicating the length of thepacket which follows. Typically, flash memory devices are programmed tohandle fixed length data packets, since such a data arrangement requiresless processing overhead in determining the length of each packet as itis processed. Furthermore, a fixed length data packet conserves spacewithin each packet, since there is no need to reserve bits that areneeded tto resolve the data packet length.

Moreover although flash memory devices primarily benefit from thepresent invention, any memory device could benefit from the presentinvention such as standard computing devices interfacing with otherdevices while the devices are operating off of battery power andcorrespondingly the current draw becomes vitally important. In thisregard, it is apparent that the tenets of the present invention can bereadily achieved with executable instructions, as opposed toelectro-mechanical devices.

Yet, with flash memory devices the tenets of the present invention aremore efficiently achieved by using electro-mechanical devices, sinceexecutable instructions can take up valuable non volatile storage spaceand further require additional processing. And, in some situations theuse of both electro-mechanical devices combined with executableinstructions may be deemed the best approach. Accordingly, the presentinvention embraces all implementations, now known or hereafterdeveloped, which efficiently transfers data between memory devices usingbit inversion techniques presented herein.

FIG. 1 shows a memory system 100 for transferring a data stream. Thesystem 100 includes a host controller 110 having a controller buffer 111and a flash controller 120 having a packet-based ones counter 121, abuffer 122, a shift/load register 123, two multiplexors 125 and 125, aflash controller finite state machine 127, and a flash chip 126. A datasource, such as controller buffer 111, transfers a data stream from ahost controller 110 to a flash controller 120. The transfer of the datastream is intercepted such that each bit associated with the data streamis inspected by a packet-based ones counter 121 as it is transferred tothe buffer 122.

Next, for each data stream transferred the bits associated with thatstream are counted and if the total number of set bits exceed the totalbits contained in the data stream, then an inversion bit is set andshifted to the shift/load register 123, otherwise an inversion bit isunset and shifted to the shift/load register 123. Once several datastreams have been received to fill the capacity of the buffer 122, thedata stream is ready to be transferred to the flash chip 126. During thetransfer process, the finite state machine 127 acting in connection withthe multiplexors 124 and 125, inverts bits associated with data streamif an inversion bit is detected from the shift/load register 123 duringthe transfer. Moreover, the inversion bit itself is inserted into thedata stream as it is transferred to the flash chip 126.

FIG. 2 shows one flowchart for methods 200 of transferring a datastream. Initially in a first method 200, at step 201 a data source isinterfaced with a target source. A data source may include, by way ofexample only, any host controller or memory device having data whichneeds to be transferred to a target source. A target source can itself,by way of example only, be a target controller or memory device. Forexample, a data source can be the host controller associated with adigital camera, wherein the data is image data associated with acaptured image within the host controller.

In step 202, a data stream is acquired from the data source. Aspreviously presented, the data stream may include any sequence of bitsin fixed or variable length chunks. In the present example, the datastream can include a chunk of data having a fixed length, e.g. of 12bytes, of data associated with the captured image data, wherein thecaptured image data has a total size of several megabytes. As depictedin method 200, the data stream is repetitively received until the end ofthe data associated with the data source is received.

As the data stream is transferred, each bit is received in step 204.Reception of each bit can be buffered in a volatile memory, although anystorage will suffice including non volatile memory. Furthermore as eachbit is received, the received bit is inspected and if the bit is set(e.g., having a value of “1”), then a counter records a bit set total(BST) in step 205 associated with the data stream. Moreover, a total bitcount (TBC) can be recorded in step 206. Of course, it will beappreciated that a TBC may not be tracked at all in fixed length datastreams since this will be readily known and correspondingly devicesimplementing method 200 will be hardcoded or hardwired to readilyacquire the value of a data stream's TBC.

In FIG. 2, each bit is transferred in step 204 until the end of acomplete data stream is received within a temporary storage in step 207.Next, a conditional logic in step 208 determines if the BST is greaterthan the TBC divided by half. And, if the evaluation of this expressionis true, then an inversion bit is set in step 211, but if the evaluationof the expression is false, then the inversion bit is unset in step 210.The inversion bit is then stored in a storage or a register of a devicein step 213, and readily associated with the data stream from which itis calculated. For example, a temporary storage can be equipped tohandle 16 data streams or packets at one time and a shift register caninclude a single two-byte word, with each bit being associated with asingle unique data stream. However, recording the inversion bit with thedata stream in the non volatile memory will require at least one bitwithin the data stream to draw current. However with the method 200presented above, it can be assured that no more than half the bitsassociated with a data stream will in fact be set. Thus, a 256 bit datastream will at most have 128 bits set. This provides reliability tomemory devices and permits more programming of data within such devices,without incurring additional power usage.

After at least one complete data stream is received within the temporarystorage and an associated inversion bit is stored within a storage or aregister, the data stream can be transferred to a target source. As eachbit within the temporary storage is transferred to a target source, theinversion bit is inspected in step 212, and if it is set the transferredbit is inverted in step 214, if it is not set the bit transfersnormally. Upon completion, the target source in step 215 includes thedata stream as it appeared when originally sent from the data source, orin an inverted format.

Continuing with the present example, the captured image is transferredto a target source, such as a compact flash card or a multimedia card(e.g., target source). In this way, the digital camera (e.g., datasource) captures the image data, and the data can be transferred infixed byte streams to a volatile memory. As it is transferred eachstream, is assigned a calculated inversion bit based on an BST which istabulated in parallel as the stream is transferred to the volatilememory. Next, the stream is transferred to the compact flash ormultimedia card and inverted as it is transferred if the inversion bitassociated with the stream is set. As is apparent, this results in lesspower consumption during the data transfer, and correspondingly thethroughput associated with data transfer is increased.

Further, the data stream transferred in method 200 to a target sourcemay itself include a reserved bit for the inversion bit of the presentinvention, or alternatively a separate data stream which is readilyidentifiable within the target source can be used to record which datastreams within the target source are streams which have been inverted.In this way, when the data streams are read from the target source anyrestoring inversion may be readily achieved as needed.

Alternatively, FIG. 2 shows another method 200 of transferring a datastream, wherein a data source includes data streams which havepreviously underwent an inversion method 200, as discussed above. Inthis situation, what was previously discussed as being the data targetis now a data source, and what was previously discussed as being a datasource is now a data target. In the present example, the compact flashor multimedia card (e.g., data source) is inserted into a digital camera(e.g., target source) for purposes of displaying an image contained onthe card within a display associated with the camera. Therefore, targetand source are relative and transitory being resolved with the operation(e.g., read or write operation) being performed within the memorydevices.

Again, in step 203 a data stream and its associated inversion bit areacquired, with the inversion bit inspected in step 212. If the inversionbit is set then in step 214 the data stream is inverted as it istransferred to the target source in step 215, otherwise the data streamis transferred normally to the target source.

FIG. 3 shows a schematic diagram 300 of functional data 320 operable tobe inverted. The functional data 320 includes one or more data streams321 with each data stream 321 having a plurality of bits 322 and eachdata stream 321 associated with an inversion bit 330. The functionaldata 320 is received from a data source 310, and each bit 322 associatedwith a single data stream 321 is transferred to a temporary storage instep 340 and interrogated in step 341. Moreover, a total number of setdata stream bits is tabulated and compared in step 342 to the totalnumber of bits within the data stream 321, such that if the total numberof set bits exceeds more than half of the total number of bits in step342 then the inversion bit 330 associated with the data stream 321 isset, otherwise the inversion bit 330 is not set.

Further, as the data stream 321 is transferred from the temporarystorage in step 340, the calculated inversion bit 330 is inspected instep 350 and if the inversion bit 330 is set, then the data stream 321is inverted in step 351 as it is transferred to a target source in step352. Moreover, the temporary storage can house one or more data streams321 and one or more inversion bits 330 associated therewith. In thisway, the data streams 321 can be optimally buffered within the temporarystorage.

As is apparent, the functional data 320 can be logically associated inany manner within a computer readable medium, such as and by way ofexample only, a stream of data with a reversed bit to identify whetheran inversion is to take place, or as a data structure (e.g., tree,linked list, and the like) with the reserved bit or flag separatelystored in a different structure or different location (e.g., remotestorage). Of course, the reserved inversion bit or flag can be includedwithin the data structure itself.

FIG. 4 is one schematic diagram of inversion data transfer systems 400.One system 400 includes a data source device 410, a temporary storage440, a target source device 450, and a controller 420. As previouslypresented, the data source device 410 can itself be a host controllerhaving a controller storage buffer. Moreover, although FIG. 4 depicts asingle controller 410, it is readily appreciated that a singlecontroller 410 is not required, as one or more controllers can be usedand interfaced with one another to achieve results of a singlecontroller. For example, controller 420 of FIG. 4 can be designed toinclude a receiving controller, a counting controller, and atransferring controller without departing from the present invention.

Further as is readily apparent to those skilled in the art, the datasource device 410, the temporary storage 440, and the target sourcedevice 450 can be readily assembled and interfaced with the controller420 by well known connections and techniques known to those skilled inthe art such as, and by way of example only, a data bus, and the like.Also, each device depicted in systems 400 is operable to receive datarequests from the controller 420, such that data is readily passed amongthe devices through the controller 420. An example flow of the datatransfer and processing as it is handled by the controller 420, isdepicted within the controller 420 of FIG. 4. Accordingly, physicalconfigurations of controllers using electro-mechanical devices, can bereadily deployed by those skilled in the art, so as to achieve the dataflow depicted within controller 420 of FIG. 4.

Moreover, the controller 420 of system 400 receives a data stream inblock 421, wherein the bits associated with the data stream areintercepted and the set bits associated with the data stream aretabulated in block 424, by using for example a packet based ones counterdevice well known to those skilled in the art. If the total set bitswithin the data stream exceed more than half the total bits associatedwith the data stream, then a set inversion bit is set in block 424 andstored in a register or store in block 425. Again, this storage can beachieved by using a standard shift/load register, such that multiplestreams are housed in a buffer within the controller 420, and each bitshifted to the register is also associated with a single stored stream.

Once one or more streams are buffered within the temporary storage 440and a corresponding inversion bit(s) is/are associated and stored withinthe register or storage area in block 425, the stream(s) is/are ready tobe transferred to target source device 450, after being received by thecontroller 420 in block 429. During this transfer, the inversion bit isacquired in block 426 from the register or storage area in block 425.Next, if the inversion bit is set in block 427, each bit associated withthe data stream is inverted in block 428 as it is transferred in block430 to the target source device 450. As one skilled in the art willappreciate, in flash memory devices this inversion can be readilyachieved by using multiplexors attached to the shift/load register andthe storage buffer prior to transfer to the target source device 450.

Alternatively, another system 400 of FIG. 4 shows a controller 420 whichacquires an inversion bit in block 422 from the data source device 410.This inversion bit can be physically included within the received datastream in block 421 or the inversion bit can be logically associatedwith the received data stream in block 421, and thus acquired from thedata source device 410. In this embodiment, the acquired inversion bitin block 422 is stored in a register or storage area in block 425 whilethe received data stream in block 421 is transferred in block 423 andoptionally buffered in a temporary storage 440. Next, as the data streamis transferred to a target source device 450 the inversion bit isacquired in block 426 from the register or storage area in block 425 andinspected in block 427, such that if the inversion bit is set the datastream is inverted in block 428 and transferred in block 430 to thetarget source device 450, otherwise the data stream is transferred inblock 430 normally to the target source device 450.

FIG. 5 shows one flowchart for a method 500 of inverting transferreddata. In FIG. 5, a set of executable instructions reside on a computerreadable medium 500. Of course as will be readily apparent to thoseskilled in the art, the executable instructions need not reside on anysingle computer readable medium, as it can be that the instructions arehoused on multiple computer readable media and operable to be logicallyassociated and execute as a cohesive unit of instructions. Initially,the executable instructions acquires a data stream in step 501.

Data stream acquisition can occur from any data source device such as,and by way of example only, a host controller device having dataresiding thereon, a removable flash memory device having data residingthereon, and others. As this data stream is received, the bitsassociated with the stream are inspected in step 504 until the stream iscompletely received within a data storage in step 502, in order todetermine whether the stream has a total number of set bits (TSB) whichexceed more than half the total number of bits (TB) within the datastream, in which case a flag or bit is set (e.g., TSB>TB/2) or unset(e.g., TSB<=TB/2) and associated with the data stream.

At some later point in time, the data stream is transferred, in whichcase the flag or inversion bit is inspected in step 503 and transferredin step 505. Further, if the flaf or inversion bit is set, then the datastream is inverted in step 506 during the transfer step occurring instep 505. As previously discussed, the data is transferred to any targetdevice such as, and by way of example only, a host controller device, aremovable flash memory device, and others.

FIG. 6 shows one schematic diagram for a system 600 for transferring adata stream. The system 600 includes a control buffer 610, a storagebuffer 620, an inversion flag storage 630, a counting set of executableinstructions 640, and a transfer set of executable instructions 650.Again, the control buffer 610, the storage buffer 620, and the inversionstorage 630 are readily interfaced to counting instructions 640 andtransfer instructions 650 using well known techniques known in the art,such as standard device driver executable instructions permitting accessto the physical devices, and the like. Data flow, as it is received bythe counting instructions 640 and transfer instructions 650, is depictedin FIG. 6.

In system 600, a data stream is received in block 641 to a storagebuffer 620 from a control buffer 610. Moreover, one or more streams canbe received and buffered until all data within the control buffer 610 isreceived. The counting set of executable instructions 640, interceptsand inspects each bit as it is received to the storage buffer 620. Setbits within the data stream are counted in block 644 and simultaneouslytransferred to the storage buffer 620. After the data stream iscompletely received, a bit set total is compared in block 642 todetermine if it exceeds more than half the total bits within the datastream. Appropriately, an inversion bit is set in block 645 or not setin block 646 and transferred in block 643 to the inversion storage 630.

Moreover, the transfer set of executable instructions 650 acquires aninversion bit from the inversion storage in block 630 and a data streamin block 653 from the storage buffer 620, and if the inversion bit isset in block 651 then as the data stream is transferred in block 654 itis inverted in block 652.

FIG. 7 shows one schematic diagram for a memory apparatus 700. Thememory apparatus 700 includes a controller 720 which is operable toacquire from a host controller 710 a data packet residing in a storagein block 711 of the host controller 710. As will be appreciated,reception of the data packet may be achieved through infraredcommunication, hardwired communication, radio frequency communication,any wireless communication, and any hardwired communications (e.g.,direct or indirect). The controller 720 receives the data packet inblock 722 in a volatile memory (e.g., DRAM, SRAM, RAM, and others), or anon volatile memory (e.g., buffer, and others). As the data packet isreceived it is intercepted and the bits are inspected and a total setbit count tabulated in block 723. If the total set bit count exceedsmore than half the total bit count associated with the packet then aninversion bit is set, otherwise the inversion bit is not set. In eithercase, the inversion bit is associated with the data packet.

Next, as the data packet is further transferred from a temporary storagearea in block 722 to a data packet storage in block 721, if acorresponding inversion bit is set the data packet is inverted in block724 during the transfer. Moreover, although the data packet storage isdepicted, for purposes of illustration only, within the controller 720of FIG. 7 it is readily apparent that this need not be the case, as thedata storage can include removable or remote computer readable storage.

Alternatively, the controller 710 detects a data packet beingtransferred having an associated inversion bit in block 723 andseparates the bit out from the buffer. Then in a similar manner, as thedata packet is transferred from the buffer to the data packet storage inblock 721, the packet is inverted in block 724 if the inversion bit isset.

FIG. 8 shows one schematic diagram 800 for a state machine 840. Theapparatus 800 having an inversion bit 810, a data packet 820, a targetdevice 850, and a state machine 840. The state machine 840 initiallyreceives in step 830 a packet 820 and an inversion bit 810 where theyare separated in step 831. The inversion bit 810 is stored in step 832and the packet 820 is stored in step 833 in separate physical or logicallocations. Next, once a complete packet 820 is received or detected instep 836, then a transfer request state is initiated in step 835resulting in the inversion bit 810 being retrieved in step 834. Theinversion bit 810 is queried in step 837 to determine if it is set, andif it is set the packet 820 is inverted in step 838 as it is transferredin step 839. If the inversion bit 810 is not set then it is transferredin step 838 without inversion. Transfer is made to a target device 850.

CONCLUSION

It has been shown that the efficiency and throughput associated withdata transfers occurring between memory devices can be greatly improvedwith the present invention. Furthermore, current draw is reduced duringa data transfer and correspondingly less power is consumed with thetenets of the present invention. Moreover, as discussed herein thetenets of the present invention can be readily deployed usingelectro-mechanical devices and/or executable instructions. Althoughspecific embodiments have been illustrated and described herein, it willbe appreciated by those of ordinary skill in the art that anyarrangement which is calculated to achieve the same purpose may besubstituted for the specific embodiment shown. For example, althoughexamples presented herein refer to counting and inverting set bitsassociated with data, it is readily appreciated that for technologywhich programs unset bits (e.g., NAND, and the like), the tenets of thepresent invention may be easily used to count and invert unset bits. Inthis way, a set bit may be said to have a value of “0” and an unset bita value of “1”. This application is intended to cover any adaptations orvariations of the present invention. Therefore, it is manifestlyintended that this invention be limited only by the claims and theequivalents thereof.

1. A method, comprising: acquiring bits of a data stream from anexternal device to a temporary storage associated with a differentdevice and the external device and the different device include theirown storage capabilities, and the temporary storage is equipped toconcurrently handle multiple additional data streams with the handlingof the data stream, the data stream includes some reserved bits or bytesat the front of the data stream that indicates the length of each packetcomprising the data stream, and each packet is of variable length, eachdata stream being 256 bits and the temporary storage equipped to handle16 data streams, one of which is the data stream and remaining datastreams are the additional data streams; counting each bit and each setbit in a bit-set total as each bit is acquired from the external deviceand wherein the data stream remains unchanged in the external device;and setting an inversion flag for the data stream when the bit-set totalis more than half a total bit count for the bits, the inversion flag ismaintained in a shift/load register, the inversion flag is inserted intothe data stream when the data stream is subsequently transferred, theexternal device is a digital camera.
 2. The method of claim 1 furthercomprising, inverting the bits of the data stream as the data stream istransferred to a target device when the inversion flag is set.
 3. Amethod, comprising: acquiring a data stream that is to be transferred toan external and target device, which is a digital camera wherein thedata stream is transferred to the external and target device from atemporary storage associated with a different device and the externaland target device and the different device include their own independentstorage capabilities, and the temporary storage is equipped toconcurrently handle multiple additional data streams with the handlingof the data stream; inspecting an inversion flag associated with thedata stream, the inversion flag is acquired from storage; and invertingeach bit of the data stream as it is transferred to the external andtarget device when the inversion flag is set, and the target deviceincludes a data stream that is different from the data stream in thetemporary storage after the inverted transfer, and inversion flag isinserted into the data stream when it is transferred and some bits orbytes are reserved in the data stream to identify a length of eachpacket being transferred that comprise the data stream, each packet isof variable length.
 4. The method of claim 3 further comprising,transferring each bit of the data stream unchanged when the inversionflag is not set.
 5. A method, comprising: counting bits being receivedfrom an external device into temporary storage to assemble a total bitcount for a data stream associated with the bits, the total bit countmaintained as a total-bit counter on a different device from that of theexternal device, and the external device and the different deviceinclude their own storage capabilities, and the temporary storage isequipped to concurrently handle multiple additional data streams withthe handling of the data stream, the data stream and the additional datastreams received in variable length chunks, where each packet receivedfor the data stream and the additional data stream includes somereserved bits or bytes that identify a length for each packet, and eachpacket is a variable length; counting each bit that is set to assemble atotal set-bit count for the bits of the data stream; and setting aninversion flag, within a shift/load register, to be associated with thedata stream when the total set-bit count is greater than one-half of thetotal bit count, and wherein the data stream of the external deviceremains unchanged and is inverted when transferred via radio frequencyfrom the temporary storage to the different device when the totalset-bit count is greater than one-half of the total bit count, andwherein the inversion flag is inserted into the data stream when it istransferred.
 6. The method of claim 5 further comprising, supplying theinversion flag when the data stream is transferred out of the temporarystorage.
 7. The method of claim 5 further comprising, inverting each bitof the data stream when the inversion flag is set and when the datastream is transferred out of the temporary storage to a target device.8. A method, comprising: receiving a request to transfer a data streamto an external target device, the data stream is transferred to theexternal target device from a temporary storage associated with adifferent device and the external target device and the different deviceinclude their own independent storage capabilities, and the temporarystorage is equipped to concurrently handle multiple additional datastreams with the handling of the data stream, and each data streamincludes a series of packets, each packet including reserved bits orbytes to indicate a length for that packet, and each packet is ofvariable length; acquiring an inversion flag for the data stream from ashift/load register, the shift/load register maintaining a two-byte wordhaving the inversion flag as part of that two-byte word and theinversion flag maps to the data stream and remaining bits of thetwo-byte word map having each bit corresponding to a different inversionflag being maintained for the additional data stream in the shift/loadregister; and concurrently inverting each bit of the data stream as itis transferred to the external target device when the inversion flag isset, and wherein the external target device receives an inverted versionof the data stream from that which is in the temporary storage, and theinversion flag is inserted into the data stream when it is transferredto the external target device, each bit transferred via infraredcommunication.
 9. A method, comprising: recording total bit counts fordata streams being received from external devices into a buffer storage,and the buffer storage is associated with a different device from thatwhich is associated with the external devices and the external devicesand the different device include their own storage capabilities, and thebuffer storage is equipped to concurrently handle multiple additionaldata streams with the handling of the data stream, each data streamincludes multiple packets and each packet includes some reserved bits orbytes that identify a length for that packet, and each packet is ofvariable length; counting total set-bit counts for the data streamsrepresenting total bits set within the data streams, a separate totalset-bit count maintained for each of the data streams; generating andassigning values to inversion flags for the data streams, and housingthe inversion flags in a register as a byte word; and setting theassigned values for the inversion flags in response to whether a givendata stream has a total bit-set count that exceeds half of the its totalbit count, and the data stream of the external devices remain unchangedand is inverted when wirelessly_transferred from the temporary storageto the different device when the total set-bit count is greater thanone-half of the total bit count, and the inversion flags are insertedinto the data stream when the data streams are transferred to thedifferent device.
 10. The method of claim 9 further comprising,inverting each data stream as it is transferred out of the bufferstorage to target devices when its inversion flag is set.